Recording method, recording apparatus, and recording medium

ABSTRACT

The present invention is a recording method for recording data to a disc shaped record medium  10  corresponding to a hierarchical file system, the method comprising the steps of recording management information for managing a hierarchical structure of the file system to a particular area  16  of the disc shaped record medium, treating an unused area of the particular area  16  as a particular file, and recording information with respect to an initial location and an initial length of the particular file and information with respect to a current location and a current length of the particular file to the particular area  16.

TECHNICAL FIELD

[0001] The present invention relates to a recording method for recordingdata on a rewritable record medium, in particular, to a recording methodthat allows hierarchical structure management information for a filesystem and information that represents a record location of entity dataof a file to be recovered when these information gets defective. Inaddition, the present invention relates to a recording method thatallows a drive apparatus to recognize a file structure at high speedwhen data is added. Moreover, the present invention relates to arecording apparatus that uses the recording method and a record mediumon which data has been recorded corresponding to the recording method.

BACKGROUND ART

[0002] In recent years, high density optical discs typified by DVDs(Digital Versatile Discs) have been progressively developed andstandardized. To absorb as many different physical record formats ofvarious types of mediums as possible and provide a logical structure ofan information storage unit that has a higher commonality inapplications, UDF (Universal Disk Format) was established. A rewritableDVD-RAM (DVD-Random Access Memory) uses a logical format correspondingto the UDF. In addition, the UDF can be applied to a one-time writableCD-R and a rewritable CD-RW.

[0003] The UDF is structured with a hierarchical file system. In theUDF, with information stored under a root directory, a sub directory andan entity file are referenced. In addition, with information stored in asub directory, another sub directory and an entity file are referenced.Hereinafter, a directory is abbreviated as “Dir.”.

[0004] In other words, a record area on a disc is accessed as sectors. Asector is the minimum unit of storage. On a DVD-RAM, the disc isaccessed from the inner periphery side to the outer periphery side. Fromthe innermost periphery side, a lead-in area is formed. The lead-in areais followed by a system area. In the system area, volume information iswritten. As the volume information, VRS (Volume Recognition Sequence),MVDS (Main Volume Descriptor Sequence), LVIS (Logical Volume IntegritySequence), and AVDP (Anchor Volume Descriptor Pointer) are written.

[0005] The location of a record area at which a file entry (hereinafterabbreviated as “FE”) of the root Dir. is recognized by successivelyreferencing the AVDP, the MVDS, and the FSD. An FE is composed ofattribute information for a file or a directory and an allocationdescriptor (hereinafter abbreviated as “AD”). An AD is information of alogical address of a file or a directory and a size (length). An ADrepresents a record area at which entity data of a file is recorded or arecord area at which an entity of a directory is recorded.

[0006] At the FE of the root Dir., the AD represents a logical addressand a length of an entity of the root Dir. The root Dir. contains atleast one file identifier descriptor (hereinafter abbreviated as “FID”).With an FID, an FE of a sub directory or an FE of a file under the rootdirectory is referenced. With these FEs, the entity of the correspondingsub Dir. and the entity of the file are referenced by respective ADs. Inaddition, an entity of a sub Dir. may contain at least one FID. In otherwords, in the UDF, except for the root Dir., with FIDs and FEs aspointers, the FIDs, FEs, and entities are successively accessed andrecognized. In the UDF, FIDs, FEs, and entities can be written anyrecordable areas.

[0007] For example, on the innermost periphery of a disc, the lead-inarea is formed. On the outer periphery of the lead-in area, a systemarea is formed. The entity of the root Dir. is formed for example on theouter periphery of the system area.

[0008] Next, the case that a file is accessed from the root Dir. througha sub Dir. will be described. Corresponding to the FID of the entity ofthe root Dir., an FE of the sub Dir., the FE being at an addressphysically apart from the entity of the root Dir., is referenced.Likewise, corresponding to an AD of an FE of the sub Dir., the entity ofthe sub Dir., the entity being at an address apart from the FE of thesub Dir., is referenced. Likewise, the FID of the entity of the sub Dir.is referenced. An FE of the file, the FE being at an address apart fromthe entity of the sub Dir., is referenced. With an AD of the FE of thefile, the entity of the file, the entity being at an address apart fromthe FE of the file, is referenced.

[0009] Thus, conventionally, when information of directories and filesis dispersed on a disc, it takes a long time to read these information.To solve such a problem, it is possible to collectively record pointerinformation such as FIDs and FEs at a predetermined area of a disc.

[0010] However, in such a case, if a file is deleted from a disc, sincea corresponding FE and so forth are deleted, blank addresses take place.In this case, a file may be written to a blank address. As a result,pointer information that has been collectively written to thepredetermined area may be separated. As a result, it may take a longtime to read information of directories and files.

[0011] In addition, while the disc is being used, if any defect takesplace in hierarchical structure management information for a filesystem, the management information being composed of pointer informationsuch as FIDs and FEs, the drive apparatus cannot read the managementinformation. In addition, while the disc is being used, if any defecttakes place in an FE of a file, the FE representing a record area(location) of entity data of the file, the drive apparatus cannot readthe FE of the file. In such a case, even if any defect does not takeplace in entity data of moving picture data or audio data, since thedrive apparatus cannot read the management information or the FE of thefile, the drive apparatus cannot access the entity data.

DISCLOSURE OF THE INVENTION

[0012] Therefore, a first object of the present invention is to providea recording method that allows a file to be accessed always at highspeed without a separation of pointer information and an area for thepointer information to be recognized.

[0013] A second object of the present invention is to provide arecording method for recording management information as a file to arecord medium so that when a defect takes place in the managementinformation, with reference to the file, the management information canrecovered.

[0014] A third object of the present invention is to provide a recordingmethod for backing up an FE of a file so that when any defect takesplace in the FE of the file, with reference to the backup FE, the FE ofthe file can be recovered.

[0015] A fourth object of the present invention is to provide arecording apparatus and a record medium using these recording methods.

[0016] The present invention is a recording method for recording data toa disc shaped record medium corresponding to a hierarchical file system,the method comprising the steps of recording management information formanaging a hierarchical structure of the file system to a particulararea of the disc shaped record medium, treating an unused area of theparticular area as a particular file, and recording information withrespect to an initial location and an initial length of the particularfile and information with respect to a current location and a currentlength of the particular file to the particular area.

[0017] The present invention is a recording apparatus that records datato a disc shaped record medium corresponding to a hierarchical filesystem, the apparatus comprising a means for recording managementinformation for managing a hierarchical structure of the file system toa particular area of the disc shaped record medium, a means for treatingan unused area of the particular area as a particular file, and a meansfor recording information with respect to an initial location and aninitial length of the particular file and information with respect to acurrent location and a current length of the particular file to theparticular area.

[0018] The present invention is a disc shaped record medium on whichdata is recorded corresponding to a hierarchical file system, managementinformation for managing a hierarchical structure of the file systembeing recorded to a particular area of the disc shaped record medium, anunused area of the particular area being treated as a particular file,information with respect to an initial location and an initial length ofthe particular file and information with respect to a current locationand a current length of the particular file being recorded to theparticular area.

[0019] Thus, according to the present invention, when data is recordedto a disc shaped record medium corresponding to a hierarchical filesystem, management information for managing a hierarchical structure ofthe file system is recorded to a particular area of the disc shapedrecord medium and an unused area of the particular area is treated as aparticular file. Thus, an area to which the management information formanaging the hierarchical structure of the file system is added issecurely allocated. Consequently, the hierarchical structure of the filesystem can be read at high speed. Thus, the reproduction start time canbe remarkably reduced in comparison with the conventional method.

[0020] In addition, according to the present invention, sinceinformation with respect to an initial location and an initial length ofa particular file and information with respect to a current location anda current length of the particular file are recorded in a particulararea, a location and a length of the particular area can be securelyrecognized.

[0021] The present invention is a recording method for recording data toa record medium corresponding to a hierarchical file system, the methodcomprising the steps of recording management information for managing ahierarchical structure of the file system to a particular area of therecord medium, treating an unused area of the particular area as aparticular file, copying all the particular area to another area as itis and treating all the copied particular area as one backup file, andif a part of the management information cannot be read, reducing alength of the particular file, creating a blank portion of theparticular area, and recovering the part of the management informationthat cannot be read with data corresponding to the part of the backupfile in the blank portion of the particular area.

[0022] The present invention is a recording apparatus that records datato a record medium corresponding to a hierarchical file system, theapparatus comprising a means for recording management information formanaging a hierarchical structure of the file system to a particulararea of the record medium, a means for treating an unused area of theparticular area as a particular file, a means for copying all theparticular area to another area as it is and treating all the copiedparticular area as one backup file, and a means for reducing a length ofthe particular file, creating a blank portion of the particular area,and recovering a part of the management information that cannot be readwith data corresponding to the part of the backup file in the blankportion of the particular area, if the part of the managementinformation cannot be read.

[0023] In the recording method and the recording apparatus, sinceoriginal management information can be recovered with a backup file,even if a defect takes place in a part of the management information,entity data recorded on a record medium can be securely reproduced. Inaddition, since data to be recovered is placed in a particular area forthe original management information, after the recovery, the managementinformation can be collectively placed in the particular area. Thus,after the recovery, the hierarchical structure of the file system can beread at high speed. As a result, the reproduction start time can beremarkably reduced in comparison with the conventional method.

[0024] The present invention is a recording method for recording data toa record medium corresponding to a hierarchical file system, the methodcomprising the steps of recording management information for managing ahierarchical structure of the file system to a particular area of therecord medium, treating an unused area of the particular area as aparticular file, dually recording information that designates a recordlocation of entity data of a file as regular information and backupinformation to the record medium, and reducing a length of theparticular file, creating a blank area of the particular area, andrecording designation information that designates record locations ofthe regular information and the backup information to the blank area ofthe particular area.

[0025] The present invention is a recording apparatus that records datato a record medium corresponding to a hierarchical file system, theapparatus comprising a means for recording management information formanaging a hierarchical structure of the file system to a particulararea of the record medium, a means for treating an unused area of theparticular area as a particular file, a means for dually recordinginformation that designates a record location of entity data of a fileas regular information and backup information to the record medium, anda means for reducing a length of the particular file, creating a blankarea of the particular area, and recording designation information thatdesignates record locations of the regular information and the backupinformation to the blank area of the particular area.

[0026] In the recording method and the recording apparatus, sinceinformation that designates a location of entity data of a file isdually recorded, the security of the information can be improved.

[0027] In addition, according to the present invention, when regularinformation cannot be read due to an occurrence of a defect, usingbackup information, the regular information can be newly recovered tothe record medium. Thus, even if the regular information cannot be read,entity data of a file can be read. In addition, whenever regularinformation cannot be read, it is recovered with backup information.Thus, unless both the regular information and the backup informationcannot be read, entity data of a file can be read.

[0028] According to the present invention, the recording method furthercomprises the steps of copying all the particular area to another areaas it is and treating all the copied particular area as one backup file,and if a part of the management information cannot be read, reducing alength of the particular file, creating a blank portion of theparticular area and recovering the part of the management informationthat cannot be read with data corresponding to the part of the backupfile in the blank portion of the particular area.

[0029] In the recording method, since original management informationcan be recovered with a backup file, even if a defect takes place in apart of the management information, entity data recorded on a recordmedium can be securely reproduced. In addition, since data to berecovered is placed in a particular area for the original managementinformation, after the recovery, the management information can becollectively placed in the particular area. Thus, after the recovery,the hierarchical structure of the file system can be read at high speed.As a result, the reproduction start time can be remarkably reduced incomparison with the conventional method.

[0030] According to the present invention, the recording method furthercomprises the step of recording information with respect to an initiallocation and an initial length of the particular file and informationwith respect to a current location and a current length of theparticular file to the particular area.

[0031] In the recording method, since information with respect to aninitial location and an initial length of the particular file andinformation with respect to a current location and a current length ofthe particular file is recorded to the particular area, a location and alength of the particular area can be securely recognized.

BRIEF DESCRIPTION OF DRAWINGS

[0032]FIG. 1 is a schematic diagram showing the relation between alogical format of a disc shaped record medium and the disc shapethereof;

[0033]FIG. 2 is a schematic diagram for explaining a method for creatingan SMF in an SMA-2 area according to a first embodiment of the presentinvention;

[0034]FIG. 3 is a schematic diagram for explaining a method for adding asub directory after a format process has been performed;

[0035]FIG. 4 is a first part of a schematic diagram for explaining aprocess for adding a file under a root directory after a format processhas been performed according to the first embodiment;

[0036]FIG. 5 is a second part of a schematic diagram for explaining aprocess for adding a file under a root directory after a format processhas been performed according to the first embodiment;

[0037]FIG. 6 is a schematic diagram for explaining a state that a secondentity of an SMF has run out according to the first embodiment;

[0038]FIG. 7 is a schematic diagram for explaining a process forextending the second entity of the SMF according to the firstembodiment;

[0039]FIG. 8 is a first part of a schematic diagram for explaining amethod for deleting a sub directory that has been added after a formatprocess had been performed according to the first embodiment;

[0040]FIG. 9 is a second part of a schematic diagram for explaining amethod for deleting a sub directory that has been added after a formatprocess had been performed according to the first embodiment;

[0041]FIG. 10 is a block diagram showing the structure of an example ofa drive apparatus;

[0042]FIG. 11 is a schematic diagram for explaining the structure of anSMA-2 after a format process has been performed according to a secondembodiment;

[0043]FIG. 12 is a schematic diagram for explaining a method for addinga sub directory and a file after a format process has been performedaccording to the second embodiment;

[0044]FIG. 13 is a schematic diagram showing states of an SMA-2 area, anSMA-4 area, and a backup file in the case that a second entity of an SMFhas been extended according to the second embodiment;

[0045]FIG. 14 is a schematic diagram for explaining a process forrecovering an FE of a sub Dir. in that case that a defect has takenplace in the FE of the sub Dir. according to the second embodiment;

[0046]FIG. 15 is a schematic diagram for explaining a process forrecovering an entity of a sub Dir. in the case that a defect has takenplace in the entity of the Sub Dir. according to the second embodiment;

[0047]FIG. 16 is a schematic diagram for explaining the structures of anSMA-2 area and an SMA-3 area before a backup of a file entry of a childfile is created according to a third embodiment;

[0048]FIG. 17 is a schematic diagram showing a file identifierdescriptor according to the third embodiment;

[0049]FIG. 18 is a schematic diagram for explaining a creation of abackup of a file entry of a child file according to the thirdembodiment;

[0050]FIG. 19 is a schematic diagram showing a format of animplementation use according to the third embodiment; and

[0051]FIG. 20 is a schematic diagram for explaining a process forrecovering a file entry of a child file in which a defect has takenplace according to the third embodiment.

BEST MODES FOR CARRYING OUT THE INVENTION

[0052] Next, with reference to the accompanying drawings, embodiments ofthe present invention will be described. In each drawing, similarstructure is denoted by similar reference numeral.

[0053] (First Embodiment)

[0054] According to a first embodiment of the present invention,management information is collectively recorded in a predetermined area.Thus, even if data is added or deleted, a drive apparatus can recognizea file structure at high speed.

[0055]FIG. 1 is a schematic diagram showing the relation between alogical format of a disc shaped record medium and the disc shapethereof.

[0056]FIG. 2 is a schematic diagram for explaining a method for creatingan SMF in an SMA-2 area according to the first embodiment.

[0057] In FIG. 1, a logical format of a disc shaped record medium 10 isbased on UDF (Universal Disk Format). On the disc shaped record medium10, a lead-in area 11 is formed on the innermost periphery thereof. Onthe outer periphery of the lead-in area 11, logical sector numbers(hereinafter abbreviated as LSNs) are assigned. A volume informationarea 12, an SMA (Space Management Area)-1 area 15, an SMA-2 area 16, anSMA-3 area 17, and a volume information area 13 are successively formed.On the outermost periphery, a lead-out area 14 is formed. The logicalsector number of the beginning sector of the volume information area 12is “0” as a reference sector. On the other hand, logical block numbers(hereinafter abbreviated as “LBNs”) are assigned to the SMA-1 area 15 tothe SMA-3 area 17 in such a manner that the logical block number of thebeginning sector of the SMA-1 area is “0” as a reference block.

[0058] Corresponding to the prescription of the UDF, the VRS, the MVDS,and the LVIS are written in the volume information area 12. At LSN 256of the volume information area 12, the AVDP is placed. In addition, theAVDP is written to a sector having the last logical sector number and asector having (last logical sector number—256). The content of the MVDSis written as an RVDS (Reserve Volume Descriptor Sequence) twice in thevolume information area 13 on the inner periphery of the lead-out area14.

[0059] A partition area is formed between sectors having logical sectornumber 272 and (last logical sector number—272). The SMA-1 area 15 tothe SMA-3 area 17 are formed in the partition area. Corresponding to theprescription of the UDF, the SMA-1 area 15 formed on the innermostperiphery side of the partition area is composed of an FSDS (File SetDescriptor Sequence) and an SBD (Space Bitmap Descriptor). The FSDS iscomposed of an FSD (File Set Descriptor) and a TD (TerminatingDescriptor). The SBD contains information that represents the entireblank areas of the disc shaped record medium 10. A blank area of eachsector is represented with a flag. The FSD represents a logical addressand a length of an FE (File Entry) against the root Dir. in thehierarchical structure of the file system.

[0060] In FIGS. 1 and 2, the SMA-2 area 16 is an area in which the FE ofthe root Dir., the entity of the root Dir., an FE of an SMF (SpaceManagement File), and an entity of the SMF are placed. As will bedescribed later, when a required amount of the entity of the SMF isreduced, an FE of a sub Dir. and an entity of the sub Dir. that containsan FID that represents a file are placed in the SMA-2 area 16. In otherwords, the FID and the FE of the directory are collectively recorded inthe SMA-2 area 16.

[0061] The SMF is composed of two entities. The two entities arerepresented by AD-0 and AD-1 in the FE of the SMF. The first entity ofthe SMF is an area that describes information of a location (logicaladdress) and a length of an area that has been initially allocated asthe second entity of the SMF. In FIG. 2, the first entity of the SMF isan area denoted by the AD-0. As will be described later, the secondentity of the SMF is an area allocated for an FID and an FE of adirectory created while data is recorded on the disc shaped recordmedium 10 after a format process has been performed. In FIG. 2, thesecond entity of the SMF is an area represented by the AD-1.

[0062] Thus, since the SMF is divided into two entities and informationof an initial location and an initial length of the second entity aredescribed in the first entity, regardless of a location at which the FEof the SMF has been recorded and a location at which the FE of the rootDir. has been recorded, the SMA-2 area 16 can be defined. In addition,as will be described later, with the two entities of the SMA, after asub Dir. and a file under the root directory have been deleted, thedrive apparatus can flexibly operate.

[0063] In the SMF, when a format process is performed, an unused area ofthe SMA-2 area 16 is allocated as a file that has a predeterminedcapacity and to which a predetermined attribute has been added. Since anunused area of the SMA-2 area 16 is treated as a file, with the forgoingSBD, the unused area can be prevented from being recognized as a blankarea.

[0064] The FE of the root Dir., the entity of the root Dir., and the FEof the SMF can be placed at any sectors of the SMA-2 area 16. However,to access them at high speed, as shown in FIG. 1, it is preferred tosuccessively record them. Of course, one object of the present inventionof which the drive apparatus recognizes at high speed a sector forinformation recorded on the disc shaped record medium 10 can beaccomplished with the SMF.

[0065] As was described in the foregoing Related Art section, an FErepresents a location and a length of an entity of a file or adirectory. An AD of the FE describes these information. An FIDrepresents a location and a length of an FE with a name of a file or adirectory and an ICB (Information Control Block) of the FID.

[0066] The SMA-3 area 17 is an area for an FE of a file and data of thefile. In the SMA-3 area 17, it is preferred to successively place an FEof a file and data of the file corresponding thereto at adjacentaddresses. When a file is added, it is preferred to successively placean FE of the file to be added and an existing file at adjacentaddresses. In addition, it is preferred to successively place data ofthe file and the FE thereof at adjacent addresses. When an FE of a fileand data thereof are successively placed at adjacent addresses, the filecan be accessed at high speed.

[0067] Next, an example of a method for formatting the disc shapedrecord medium 10 will be described. It is assumed that the lead-in area11 and the lead-out area 14 have been created in a press process of afabrication process of the disc shaped record medium 10. In other words,it is assumed that before a format process has been performed, thelead-in area 11 and the lead-out area 14 have been formed. The formatprocess is performed from the inner periphery side to the outerperiphery side of the disc shaped record medium 10.

[0068] When the format process is started, the AVDP is written to aplurality of predetermined addresses. The forgoing VRS, MVDS, and LVISare written from the outer periphery of the lead-in area 11.

[0069] Next, a partition is created. In the partition, the SMA-1 area 15is created. The FSD is written to the SMA-1 area 15. The location of theroot Dir. is decided. Next, the SBD is created. At that point, the areaof the SBD is treated as a used area. As a result, an area of the SMF isallocated.

[0070] After the SBD and the SMA-1 area 15 have been created, the SMA-2area 16 is created from the outer periphery of the SMA-1 area 15.

[0071] When the SMA-1 area 15 is created, corresponding to the FSDwritten to the SMA-1 area 15, a sector for an FE of a root Dir. and asector for an entity of the root Dir. are successively allocated atpredetermined adjacent addresses. The FE of the root Dir. and the entityof the root Dir. are written to these addresses.

[0072] The entity of the root Dir. is composed of an FID of a parentDir. and an FID of an SMF. The FID of the SMF designates a location ofthe FE of the SMF.

[0073] At that point, an attribute of the SMF is designated in the FID.The designated attribute of the SMF prevents another apparatus or an OS(Operating System) from deleting, rewriting, or moving the SMF. Forexample, “hidden file attribute” is designated as an attribute of theSMF. The “hidden file attribute” is an attribute that prevents a filetherewith from being browsed in a normal manner.

[0074] Next, the FE of the SMF is created. When a format process isperformed, the FE of the SMF is composed of the AD-0 that designates anaddress and a length of a file of a first entity and the AD-1 thatdesignates an address and a length of a file of a second entity. Thus,with the FE designated, these files are created. The files can be usedas dummy files. In the FE of the SMF, “read only file attribute” and“system file attribute” are designated.

[0075] The “read only file attribute” is an attribute that representsthat a file therewith is a read only file and that the system prohibitsthe file therewith from being changed or deleted. The “system fileattribute” is an attribute that represents that a file therewith is afile required by the system. When all these three attributes aredesignated to the SMF, unless it is intentionally operated, it cannot bedeleted, rewritten, or moved. These attributes can be canceled by aknown method.

[0076] Thereafter, a first entity of the SMF is created in a sectoradjacent to the sector for the entity of the root Dir. An initiallocation and an initial length of the second entity of the SMF aredescribed in the first entity of the SMF. In other words, the locationand the length of the second entity of the SMF that has been allocatedin the format process are described in the first entity of the SMF. Thisformat is described as AD corresponding to the UDF. In thespecification, a pseudo AD is denoted by [AD]. FIG. 2 shows [AD-SMA2].As will be described later, there is a possibility of which the secondentity of the SMF is extended so that there are a plurality of [AD]. Torepresent the number of [AD], corresponding to the prescription of theUDF, an AED (Allocation Extended Descriptor) is used. In thespecification, the pseudo AED is denoted by [AED].

[0077] In such a manner, since the SMF is placed in the SMA-2 area 16, ablank area of the SMA-2 area 16 can be allocated by the SMF. After aformat process is performed, when an FE of a sub Dic. and an entitythereof are written, the area of the second entity of the SMF isreduced. The FE of the sub Dir. and the entity thereof are created inthe SMA-2 area 16.

[0078] In such a manner, the SMA-2 area 16 is created. On the outerperiphery of the SMA-2 area 16, the SMA-3 area 17 is formed. No processis performed for the SMA-3 area 17. In other words, the SMA-3 area 17 isan unused area. After a format process is performed, data of a file isrecorded in the SMA-3 area 17. The RVDS is created skipping the area forthe SMA-3 area 17. As was described above, information of the MVDS thathas been created is written twice. After the RVDS has been created, theformat process of the disc shaped record medium 10 is completed.

[0079] Next, a method for adding a sub Dir. after a format process isperformed will be described.

[0080]FIG. 3 is a schematic diagram for explaining a method for adding asub directory after a format process is performed according to the firstembodiment.

[0081] The case that a sub Dir. (new Dir.) is added in the state shownin FIG. 2 will be described.

[0082] First of all, an FID that represents a new Dir. is added to anentity of a root Dir. At that point, when a sector for the entity of theroot Dir. has a blank area, as shown in FIG. 3, the FID is added to thesector. In contrast, when the sector does not have a blank space (notshown), after the size of the area of a second entity of an SMF isreduced, the FID of the new Dir. is added to the resultant blank area.

[0083] Next, to add an FE of the new Dir., the length of the area of thesecond entity of the SMF is reduced. The FE of the new Dir. is added tothe resultant blank area.

[0084] Next, to add an entity of the new Dir. (an FID of a parent Dir.in FIG. 3), the length of the second entity of the SMF is furtherreduced. The entity of the new Dir. is added to the resultant blankarea.

[0085] Next, to reflect the change of the length of the second entity ofthe SMF, information of an AD-1 of the FE of the SMF is updated.

[0086] As a result, as shown in FIG. 3, the sub Dir. has been added tothe SMA-2 area 16. In addition, information with respect to the addedsub Dir. and information with respect to the directory that has beenrecorded are collectively recorded in the SMA-2 area 16.

[0087] Next, a process for adding a file to a root Dir. will bedescribed.

[0088]FIG. 4 is a first part of a schematic diagram for explaining aprocess for adding a file under a root directory after a format processhas been performed according to the first embodiment of the presentinvention.

[0089]FIG. 5 is a second part of a schematic diagram for explaining aprocess for adding a file under a root directory after a format processhas been performed according to the first embodiment of the presentinvention.

[0090] Next, the case that a file (new Dir.) is added to a root Dir. inthe state shown in FIG. 2 will be described.

[0091] First of all, an FID that represents a new file is added to anentity of a root Dir. At that point, when a sector for the entity of theroot Dir. has a blank space, as shown in FIG. 4, the FID is added to thesector.

[0092] In contrast, when the sector does not have a blank space, asshown in FIG. 5, the length of an area for a second entity of an SMF isreduced. The FID of the new file is added to the resultant blank area.In this case, since the length of the second entity of the SMF has beenchanged, information of an AD-1 of the FE of the SMF is updated.

[0093] Next, an FE of the new file is added to an SMA-3 area 17. Next,an entity of the new file (data of a parent file in FIGS. 4 and 5) isadded to the SMA-3 area 17. In such a manner, the FE of the file and theentity thereof are placed in the SMA-3 area 17.

[0094] As a result, as shown in FIG. 4 or 5, the new file is added tothe root Dir. In addition, information with respect to the added newfile and information with respect to an existing directory that has beenrecorded are collectively recorded in the SMA-2 area 16.

[0095] When a plurality of files are recorded, to allow them to besuccessively accessed at high speed, it is preferred to successivelyplace an FE of one file, an entity thereof, an FE of another file, anentity thereof, and so forth.

[0096] An FE of a file to be added (the file is referred to as file A)is created at an address represented by an FID added to an entity of theroot Dir. An entity of the file A is written to an address adjacent tothe FE of the address A. When file B, file C, . . . , and so forth aresuccessive written, an entity of the file B is created at an addressadjacent to the address of the entity of the file A. An entity of thefile B is written at an address adjacent to the address of the FE of thefile B. This applies to the file C. In other words, an FE of the file Cis written at an address adjacent to the address of the entity of thefile B. An entity of the file C is written at an address adjacent to theaddress of the FE of the file C.

[0097] When many sub Dirs. and new files are added to a root Dir. placedin an SMA-2 area 16, an FID of an entity of the root Dir., FEs of subDirs., and FIDs of new files of entities of the sub Dirs. are added. Asa result, it can be considered that the SMA-2 area 16 becomes full withthe added FEs and FIDs. This state is shown in FIG. 6.

[0098]FIG. 6 is a schematic diagram for explaining the state that thesecond entity of the SMF has run out according to the first embodiment.

[0099] In FIG. 6, since the second entity of the SMF has run out, anAD-1 that represents the second entity of the SMF has been lost.However, since the first entity of the SMF describes the informationwith respect to the second entity of the SMF, the drive apparatus canrecognize the location and the length of the SMA-2 area 16. As a result,the drive apparatus can recognize the relation between directories andfiles at high speed.

[0100] In this case, when the SMA-3 area 17 has a blank space, the SMA-3area 17 is divided into a plurality of SMA areas. As a result, an SMA-4area that is an extension area of the SMA-2 area 16 and an SMA-5 areaequivalent to the SMA-3 area in which data is recorded are newly createdoutside the location of a file in the SMA-3 area 17. This state is shownin FIG. 7.

[0101]FIG. 7 is a schematic diagram for explaining a process forextending the second entity of the SMF according to the firstembodiment.

[0102] In FIG. 7, since the SMA-4 area is allocated, information withrespect to the initial location and the length of the SMA-4 area isadded in the AD format as [AD-SMA4] to an entity represented by the AD-0of the SMF. As the table is added, [AED] is updated. A location and alength that represent the newly allocated SMA-4 area are added as anAD-2 to the FE of the SMF.

[0103] When a sub Dir. or a file is added to the root Dir., the forgoingoperation described with reference to FIGS. 3 to 5 is performed for thesecond entity of the SMF represented by the AD-2.

[0104] Next, the case that a sub Dir. is deleted will be described.

[0105]FIG. 8 is a first part of a schematic diagram for explaining amethod for deleting a sub directory that has been added after a formatprocess had been performed according to the first embodiment.

[0106]FIG. 9 is a second part of a schematic diagram for explaining amethod for deleting a sub directory that has been added after a formatprocess had been performed according to the first embodiment.

[0107]FIG. 8 shows the state of an SMA-2 area 16 before a sub Dir. isdeleted. FIG. 9 shows the state of the SMA-2 area 16 after the sub Dir.has been deleted.

[0108] In FIG. 8, as was described with reference to FIG. 3, after aformat process had been performed, a plurality of sub Dirs. have beenadded, FIDs of added sub Dirs. (for example, an FID of new Dir. 1, anFID of new Dir. 2, an FID of new Dir. 3, . . . , and so forth) are addedto the entity of the root Dir. Correspondingly, in a blank area of whichthe second entity of the SMF is reduced, FEs and entities of the addedsub Dirs. (for example, an FE and an entity of the new Dir. 1, an FE andan entity of the new Dir. 2, an FE and an entity of the new Dir. 3, andso forth are added).

[0109] Next, the case that a sub Dir. is deleted in such a state will bedescribed.

[0110] First of all, the drive apparatus references a first entity of anSMF represented by an AD-0 of an FE of the SMF and recognizes an initialrange of a second entity with a location and a length represented by[AD].

[0111] Next, the drive apparatus deletes an FID, an FE, and an entity ofa sub Dir. to be deleted. To reflect their deletion, an entity in whichthe FID to be deleted is described is updated.

[0112] Next, the drive apparatus determines whether or not the FE andthe entity of the sub Dir. that has been deleted are in their initialranges.

[0113] When the FE and the entity of the sub Dir. that have been deletedare in their initial ranges, since the areas for the FE and the entityof the sub Dir. that has been deleted becomes unused areas, the driveapparatus adds an AD that represents the unused areas to the FE of theSMF.

[0114] For example, in the state shown in FIG. 8, when a sub Dir. to bedeleted is the new Dir. 2, as shown in FIG. 9, the FID of the new Dir. 2is deleted from the entity of the root Dir. An AD that representssectors for the FE and entity of the new Dir. 2 is added as AD-12 to theFE of the SMF.

[0115] Since information with respect to an initial location and alength of a second entity of an SMF is described in a first entity ofthe SMF, it can be determined whether or not a sub Dir. to be deleted isin the initial range of the second entity of the SMF. When the sub Dir.to be deleted is in the initial range of the second entity of the SMF,by adding the sectors for the FE and the entity of the sub Dir. that hasbeen deleted to the FE of the SMF, the sectors can be treated as thesecond entity of the SMF. Thus, since the sectors are treated as theSMF, although they are recognized as a part of a file, when a new subDir. is added, the sectors can be used. Thus, information with respectto directories can be collected in one area.

[0116] In the forgoing example, the case that a sub Dir. is deleted wasexplained. However, when a file or an FID is deleted, if a blank sectortakes place, it is determined whether or not the blank sector is in aninitial range of the second entity of the SMF. Corresponding to thedetermined result, the forgoing process is performed.

[0117] Next, a drive apparatus according to the present invention willbe described.

[0118]FIG. 10 is a schematic diagram showing the structure of an exampleof the drive apparatus.

[0119] In this example, the foregoing disc shaped record medium 10 is arecord medium whose record layer is made of a phase change metalmaterial. Using a phase change technology of which the temperatureapplied to the record layer is controlled with the laser output that isadjusted and thereby the crystal/non-crystal states of the record layerare changed, the drive apparatus 50 records data to the disc shapedrecord medium 10.

[0120] In FIG. 10, the drive apparatus 50 comprises a spindle motor 51,an optical pickup 52, a laser driver 53, a record equalizer 54, a buffermemory 55, an encoder/decoder circuit (hereinafter abbreviated as“ENC/DC circuit”) 56, a thread mechanism 57, an RF signal processingcircuit 58, an address extraction 59, a drive controlling microcomputer60, an interface (hereinafter abbreviated as “I/F”) 61, a servo circuit62, and a memory 63.

[0121] The spindle motor 51 rotates and drives the disc shaped recordmedium 10 that has been chucked. The rotation speed of the spindle motor51 is servo-controlled by the servo circuit 62.

[0122] Data is recorded or reproduced to/from the disc shaped recordmedium 10 through the optical pickup 52. The optical pickup 52 isthread-traveled in the radius direction of the disc shaped record medium10 by the thread mechanism 57.

[0123] Data that is input from an external digital apparatus 71 issupplied to the drive apparatus 50 through the I/F 61, for example, SCSI(Small Computer System Interface). The digital apparatus 71 inputs andoutputs a digital signal. As long as the digital apparatus 71 inputs andoutputs a digital signal and complies with the interface, any digitalapparatus 71 can be used. The digital apparatus 71 is for example apersonal computer, a camera integrated portable digital video camcorder,a digital still camera, or a cellular phone. The digital apparatus 71may be built in one of those apparatuses.

[0124] The ENC/DEC circuit 56 and the drive controlling microcomputerare connected to the I/F 61. The buffer memory 55, the record equalizer54, the RF signal processing circuit 58, the servo circuit 62, and thedrive controlling microcomputer 60 are connected to the ENC/DEC circuit56.

[0125] The memory 55 is a buffer memory that stores write data or readdata. Write data is supplied from the digital apparatus 71 to theENC/DEC circuit 56 through the I/F 61. In the recording mode, theENC/DEC circuit 56 generates data in the forgoing format and encodesdata corresponding to the format. In the reproducing mode, the ENC/DECcircuit 56 performs a decoding process and outputs the decoded data tothe digital apparatus 71 through the I/F 61.

[0126] An address is added as a sub code by the ENC/DEC circuit 56. Inaddition, an address is added to a header of data.

[0127] Data that is output from the ENC/DEC circuit 56 is supplied tothe laser driver 53 through the record equalizer 54. The laser driver 53generates a drive waveform having a predetermined level necessary forrecording data to the disc shaped record medium 10. An output signal ofthe laser driver 53 is supplied to a laser device of the optical pickup52. The laser device radiates laser light having an intensitycorresponding to the output signal to the disc shaped record medium 10.As a result, the data is recorded on the disc shaped record medium 10.The laser driver 53 properly controls the intensity of the laser lightunder the control of an APC (Automatic Power Control) of the RF signalprocessing circuit 58.

[0128] In contrast, a signal generated by the optical pickup 52corresponding to light reflected from the disc shaped record medium 10is supplied to the RF signal processing circuit 58. The addressextracting circuit 59 extracts address information corresponding to thesignal supplied from the RF signal processing circuit 58. The extractedaddress information is supplied to the drive controlling microcomputer60.

[0129] A matrix amplifier of the RF signal processing circuit 58calculates a detection signal of a photo detector of the optical pickup52. As a result, the RF signal processing circuit 58 generates atracking error signal TE and a focus error signal FE. The tracking errorsignal TE and the focus error signal FE are supplied to the servocircuit 62.

[0130] The drive controlling microcomputer 60 controls a seek operationwith an address and controls a laser power with a control signal. Thedrive controlling microcomputer 60 comprises a CPU (Central ProcessingUnit), a RAM (Random Access Memory), and a ROM (Read Only Memory). Thedrive controlling microcomputer 60 controls the entire drive apparatussuch as the I/F 61, the ENC/DEC circuit 56, the RF signal processingcircuit 58, and the servo circuit 62. Thus, the drive controllingmicrocomputer 60 performs the forgoing various processes when a sub Dir.is added or deleted and a file is added or deleted. The memory 63 may beconnected to the drive controlling microcomputer 60.

[0131] In addition, an RF signal that is reproduced from the disc shapedrecord medium 10 is supplied to the ENC/DEC circuit 56. The ENC/DECcircuit 56 performs a decoding process corresponding to a predeterminedformat. In other words, the ENC/DEC circuit 56 demodulates data that hasbeen modulated in the recording mode and decodes an error correctioncode (namely, corrects an error). The ENC/DEC circuit 56 stores thereproduced data to the buffer memory 55. When the buffer memory 55receives a read command from the digital apparatus 71, the read data istransferred to the digital apparatus through the I/F 61.

[0132] The frame synchronous signal, the tracking error signal TE, andthe focus error signal FE that are output from the RF signal processingcircuit 58, and the address information that is output from the addressextracting circuit 59 are supplied to the servo circuit 62. The servocircuit 62 performs a tracking servo and a focus servo for the opticalpickup 52, a spindle servo for the spindle motor 51, and a thread servofor the thread mechanism 57.

[0133] (Second Embodiment)

[0134] According to a second embodiment of the present invention, evenif a defect takes place in management information for managing thehierarchical structure of a file system, the management information canbe recovered and read at high speed.

[0135]FIG. 11 is a schematic diagram for explaining the structure of anSMA-2 after a format process has been performed according to the secondembodiment. FIG. 2A shows an SMA-2 area, whereas FIG. 2B shows an SMA-3area, in particular, an entity of an BOS.

[0136] In FIGS. 1 and 11, a logical format of a disc shaped recordmedium according to the second embodiment is the same as the logicalformat according to the first embodiment except that an SMA-2 area 16has an FE of a BOS (Back-up Of Space management file) and an SMA-3 area17 has an entity of the BOS. Next, only the difference between thelogical format of the second embodiment and the logical format of thefirst embodiment will be described.

[0137] The SMA-3 area 17 is an area that contains an FE of a file anddata thereof. The SMA-3 area 17 also contains an entity of the BOS (dataof the BOS). The entity of the BOS is a file that backs up managementinformation that is collectively recorded in the SMA-2 area 16. As shownin FIG. 11B, the entity of the BOS is a complete copy of the SMA-2 areathat is obtained by referencing an entity of an AD-0 of an SMF. The FEof the BOS represents a location and a length of the entity of the BOS.As shown in FIG. 11A, the FE of the BOS is recorded in the SMA-2 area16. As shown in FIG. 11B, the FE of the BOS is backed up in the entityof the BOS.

[0138] Next, an example of a method for formatting the disc shapedrecord medium 10 according to the second embodiment will be described.

[0139] When a format process is started, an AVDP is written to aplurality of addresses. The forgoing VRS, MVDS, and LVIS are writtenfrom the outer periphery of a lead-in area 11.

[0140] Next, a partition is created. In the partition, an SMA-1 area 15is created. An FSD is written. The location of a root Dir. is decided.Next, an SBD is created. At that point, an area for an SMF is treated asa used area with the SBD. As a result, the area for the SMF isallocated.

[0141] After the SBD is created and then the SMA-1 area 15 is created,an SMA-2 area 16 is created from the outer periphery of the SMA-1 area15.

[0142] When the SMA-2 area 16 is created, corresponding to the FSDwritten to the SMA-1 area 15, a sector for an FE of a root Dir. and asector for an entity of the root Dir. are successively allocated atpredetermined addresses. The FE and the entity of the root Dir. arewritten to these sectors.

[0143] In the format process, the entity of the root Dir. is composed ofan FID of a parent Dir., an FID of an SFM, and an FID of a BOS. The FIDof the BOS designates the location of an FE of the BOS.

[0144] At that point, attributes of the SMF and BOS are designated inthe FIDs thereof. The designated attributes of the SMF and BOS preventanother apparatus and the OS (Operating System) from deleting,rewriting, and moving the SMF and the BOS. For example, “hidden fileattribute” is designated as an attribute of each of the SMF and BOS.

[0145] Next, the FE of the BOS is created. An AD that designates alocation and a length of an entity of the BOS are placed in the FE ofthe BOS. The length of the entity of the BOS is a length for whichinformation of the SMA-2 area 16 can be completely copied. Next, an FEof the SMF is created.

[0146] By designating the FE, the file is created. Thus, by creating theFE of the BOS and the FE of the SMF, the area for the entity of the SMFand the area for the entity of the BOS can be allocated.

[0147] In addition, both “read only file attribute” and “system fileattribute” are designated to the FE of the BOS and the FE of the SMF.When these three attributes are designated to the BOS and the SMF,unless an intentional operation is performed, the BOS and the SMF can beprevented from being deleted, rewritten, and moved.

[0148] Next, a first entity of the SMF is created in a sector adjacentto the sector for the entity of the root Dir. An initial location and aninitial length of a second entity of the SMF are described in the firstentity of the SMF.

[0149] In such a manner, when the SMF is placed in the SMA-2 area 16, ablank area of the SMA-2 area 16 can be allocated by the SMF. After theformat process is performed, when an FE of a sub Dir. and an entitythereof are written, the area for the second entity of the SMF isreduced. As a result, the FE of the sub Dir. and the entity thereof arecreated in the SMA-2 area 16.

[0150] In such a manner, the SMA-2 area 16 is created. On the outerperiphery of the SMA-2 area 16, an SMA-3 area 17 is placed. In a part ofthe SMA-3 area 17, the entity of the BOS is created. The entity of theBOS is a file of management information for managing the hierarchicalstructure of the file system. The file is recorded in the SMA-2 area 16.When the format process is performed, the entity of the BOS is composedof the FE of the root Dir., the entity of the root Dir., the FE of theBOS, the FE of the SMF, and the entity of the SMF. The entity of theroot Dir. is composed of the FID of the parent Dir., the FID of the SMF,and the FID of the BOS.

[0151] The SMA-3 area 17 excluding the entity of the BOS is an unusedarea. After the format process is performed, data of a file and so forthare recorded in the unused area. By skipping the area designated as theSMA-3 area 17, the RVDS is created. As a result, the format process forthe disc shaped record medium 10 is completed.

[0152] Next, a method for adding a sub Dir. and a file after a formatprocess has been performed will be described.

[0153]FIG. 12 is a schematic diagram for explaining a method for addinga sub directory and a file after a format process has been performedaccording to the second embodiment. FIG. 12A shows an SMA-2 area,whereas FIG. 12B shows an SMA-3 area, in particular, an entity of a BOS.

[0154] In the state shown in FIG. 11, the case that sub Dir. 1, sub Dir.X, and so forth are added will be described.

[0155] First of all, an FID representing the sub Dir. 1 is added to anentity of a root Dir. At that point, when a sector for the entity of theroot Dir. has a blank space, as shown in FIG. 12A, the FID is added tothe sector. In contrast, when the sector does not have a blank space(not shown), after a length (size) of an area for a second entity of anSMF is reduced, the FID of the sub Dir. 1 is added to the resultantblank area.

[0156] Next, to add an FE of the sub Dir. 1, the length of the secondentity of the SMF is reduced.

[0157] Next, to add an entity of the sub Dir. 1 (an FID of a parent Dir.and an FID of a child file in FIG. 12), the length of the second entityof the SMF is further reduced.

[0158] Next, to reflect the change of the length of the second entity ofthe SMF, the information of the AD-1 of the FE of the SMF is updated.

[0159] Next, to reflect the change of the SMA-2 area 16, an entity of aBOS is rewritten. In other words, the content of the SMA-2 area 16 isread and written to the area for the entity of the BOS. The entity ofthe BOS is composed of an FE of the root Dir., an entity of the rootDir., an FE of the BOS, an FE of the SMF, an entity designated by anAD-0 of the SMF, an FE of the sub Dir. 1, and an entity of the sub Dir.1. The entity of the root Dir. is composed of an FID of the parent Dir.,an FID of the SMF, an FID of the BOS, and an FID of the sub Dir. 1. Theentity of the sub Dir. 1 is composed of the FID of the parent Dir. andthe FID of the child file.

[0160] After such an operation is performed for each of the sub Dir. 2,sub Dir. 3, and so forth, the content of the SMA-2 area 16 becomes asshown in FIG. 12A.

[0161] In the forgoing process, whenever the content of the SMA-2 areais changed, the content of the entity of the BOS that backs up thecontent of the SMA-2 area is changed. However, the present invention isnot limited to such an example. Instead, the content of the entity ofthe BOS may be changed when the disc shaped record medium 10 is insertedor removed into/from the drive apparatus, whenever a predetermined timeperiod elapses, whenever the number of FIDs added to the entity of theroot Dir. exceeds a predetermined value (for example, 3), or when apredetermined command is input by the user.

[0162] In the forgoing example, the case that a directory is added wasdescribed. Next, the case that a file is added will be described.

[0163] First of all, an FID that represents a new file is added to anentity of a root Dir. At that point, when a sector for the entity of theroot Dir. has a black space, the FID is added to the sector. Incontrast, when the sector does not have a blank space, a length of anarea for a second entity of an SMF is reduced. The FID of the new fileis added to the resultant blank area. In this case, since the length ofthe second entity of the SMF has been changed, information of an AD-1 ofan FE of the SMF is updated. Next, an FE of the new file is added to anarea for an SMA-3 area 17. Next, an entity of the new file is added tothe area for the SMA-3 area 17. In such a manner, the FE and the entityof the file are placed in the SMA-3 area 17.

[0164] As a result of such an operation, the new file is added to theroot Dir. In addition, information with respect to the added new fileand information with respect to a directory that has been recorded arecollectively recorded in the SMA-2 area 16.

[0165] When many sub Dirs. and many new files are added to the root Dir.placed in the SMA-2 area 16, an FID of an entity of the root Dir., FEsof sub Dirs., and FIDs of new files in the entities of the sub Dirs. areadded. As a result, it can be considered that the added FEs and FIDscause the SMA-2 area 16 to become full.

[0166] In such a case, when the SMA-3 area 17 has a blank space, it isdivided into a plurality of SMA areas that are an SMA-4 area as anextension area of the SMA-2 area 16 and an SMA-5 area equivalent to theSMA-3 area in which data is recorded. As a result, the SMA-4 area andthe SMA-5 area are newly created on the outer periphery of the locationof a file of the SMA-3 area 17.

[0167]FIG. 13 is a schematic diagram showing states of an SMA-2 area andan SMA-4 area and a state of a backup file in the case that a secondentity of an SMF is extended according to the second embodiment. FIG.13A shows the state of the SMA-2 area in the case that the second entityof the SMF has run out. FIG. 13B shows the states of the SMA-2 area andthe SMA-4 area in the case that the second entity of the SMF has beenextended. FIG. 13C shows the state of the backup file.

[0168] In FIG. 13B, since the SMA-4 area is allocated, information withrespect to an initial location and an initial length of the SMA-4 areais added as [AD-SMA4] in AD format to an entity designated by an AD-0 ofan SMF. As the table is added, [AED] is updated. A location and a lengththat represent the newly allocated SMA-4 area are added as AD-2 to an FEof the SMF.

[0169] When an area for an backup of the content of the SMA-4 area hasnot been allocated in the SMA-3 area, an entity of a BOS is extended toan SMA-5 area (not shown). An AD that describes a location and a lengththat represent the extended entity of the BOS is added to an FE of theBOS of the SMA-2 area 16.

[0170] When a sub Dir. and a file are added to the root Dir., anoperation similar to that described with reference to FIGS. 11 and 12 isperformed for the second entity of the SMF designated by the AD-2.

[0171] When a backup file is created, as shown in FIGS. 13B and 13C,only management information placed in the SMA-2 area and the SMA-4 areais baked up. In other words, the entity of the BOS is created byreferencing [AD-SMA2] of the entity of the AD-0 of the SMF, directlycopying the SMA-2 area, referencing [AD-SMA4], and directly copying theSMA-4 area.

[0172] Next, a method for recovering an FE of a sub Dir. in managementinformation placed in the SMA-2 area in the case that the FE of the subDir. cannot be read will be described.

[0173]FIG. 14 is a schematic diagram for explaining a process forrecovering an FE of a sub Dir. in the case the a defect has taken placein the FE of the sub Dir. according to the second embodiment.

[0174]FIG. 14A shows a state that a defect has taken place in sub Dir.X. FIGS. 14B and 14C show a state that an FE of the sub Dir. X has beenrecovered in an SMA-2 area 16 using the FE of the sub Dir. X placed inan entity of a BOS.

[0175] In FIG. 14A, an FID of the sub Dir. X under a root Dir. is placedin an entity of the root Dir. The FID of the sub Dir. X designates theFE of the sub Dir. X placed in LBNb. The FE of the sub Dir. X designatesan entity of the sub Dir. X. The entity of the sub Dir. X is composed ofan FID of a parent Dir., an FID of a child file, and so forth.

[0176] When the FE of the sub Dir. X cannot be read due to a defect insuch a case, an implementation recovers management information using theentity of the BOS.

[0177] First of all, the implementation checks the LBNb that representsthe FE of the sub Dir. X, LBNx that represents the entity of the BOS,and an entity of an AD-0 of an SMF. The implementation recognizes LBNathat represents the start location of the SMA-2 area 16 by referencingthe entity of the AD-0 of the SMF.

[0178] Next, using the recognized result, the implementation checks alocation of the FE of the sub Dir. X placed in the entity of the BOS.

[0179] The implementation checks the entity of the AD-0 of the SMFbecause there is a possibility of which while the disc shaped recordmedium is being used, an FE of a sub Dir., an entity thereof, and an FIDof a file cause the SMA-2 area 16 to be extended.

[0180] Thus, in the case shown in FIG. 13C, when the implementationchecks the location of the FE of the sub Dir. X placed in the entity ofthe BOS, assuming that LBN of the FE of the sub Dir. X represented bythe FID is LBNb, the implementation determines an initial location ofthe LBNb in the second entity of the SMF. In other words, theimplementation determines whether the LBNb is in the SMA-2 area with[AD-SMA2] or in the SMA-4 area with [AD-SMA4]. As a result, theimplementation obtains an offset value from the LBN a. In other words,when the LBNb is in the SMA-2 area, the offset value is (LBNb−LBNa).When the LBNb is in the SMA-4 area, the offset value is (length of SMA-2area)+(LBNb−(start LBN of SAM-4 area)). The offset value is denoted by f(LBNb, [entity of AD-0 of SMF]). In is case, y=f (x) represents that yis a function of x.

[0181] When the SMF is not extended, the location of the FE of the subDir. X is LBNx+(LBNb−LBNa). When offset value=f (LBNb, [entity of AD-0of SMF]) is calculated with the LBNX, the implementation can recognizethe FE of the sub Dir. X placed in the entity of the BOS.

[0182] Next, the implementation reads the FE of the sub Dir. X from theentity of the BOS.

[0183] Next, to add the FE of the sub Dir. X that has been read, theimplementation reduces the length of the area for the second entity ofthe SMF, changes the descriptor tag in a predetermined manner, and addsthe FE of the sub Dir. X to the resultant blank area.

[0184] Next, to reflect the change of a length of the second entity ofthe SMF, the implementation updates the information of an AD-1 of an FEof the SMF.

[0185] Next, to reflect the change of a location of the FE of the subDir. X, the implementation rewrites an FID of the sub Dir. X.

[0186] Next, to prohibit a defective sector from being accessed, theimplementation causes the defective sector to be excluded from the SMFthat is managed. In other words, the implementation excludes thedefective sector from an entity of an AD-0 of the SMF, the entitydefining the initial area of the SMF.

[0187] Next, to reflect the change of an SMA-2 area 16, theimplementation rewrites the entity of the BOS.

[0188] In such a manner, when the entity of the BOD as a backup of theFE of the sub Dir. X is referenced and the length of the area for thesecond entity of the SMF is reduced, the defective FE of the sub Dir. Xcan be recovered in the management information placed in the SMA-2 area16. Thus, even if the defective FE of the sub Dir. X is recovered, themanagement information can be collectively placed in the SMA-2 area 16.

[0189] Next, a method for recovering an entity of a sub Dir. inmanagement information placed in an SMA-2 area 16 in the case that theentity of the sub Dir. 1 cannot be read will be described.

[0190]FIG. 15 is a schematic diagram for explaining a process forrecovering an entity of a sub Dir. in the case that a defect has takenplace in the entity of the sub Dir. according to the second embodiment.

[0191]FIG. 15A shows a state that a defect has taken place in an entityof sub Dir. X. FIGS. 15B and 15C shows a state that the entity of thesub Dir. X is recovered to an SMA-2 area 16 using the entity of the subDir. X placed in an entity of a BOS.

[0192] In FIG. 15A, an FID of the sub Dir. X under a root Dir. is placedin an entity of the root Dir. The FID of the sub Dir. X designates an FEof the sub Dir. X. The FE of the sub Dir. X designates the entity of thesub Dir. X placed in LBNC. The entity of the sub Dir. X is composed ofan FID of a parent Dir., an FID of a child file, and so forth. The FIDof the parent Dir. designates an FE of sub Dir. 1. The FID of the childfile designates an FE of a child file placed in an SMA-3 area 17. The FEof the child file designates entity data o the child file.

[0193] In such a case, if the entity of the sub Dir. X cannot be readdue to a defect, the drive apparatus recovers management informationusing an entity of a BOS.

[0194] First of all, the implementation checks LBNC that designates theentity of the sub Dir. X, LBNx that designates the entity of the BOS,and an entity of an AD-0 of an SMF.

[0195] Next, with the checked result, the implementation calculates anoffset from the LBNx and obtains a location of the entity of the subDir. X placed in the entity of the BOS.

[0196] Next, the implementation reads the entity of the sub Dir. X fromthe entity of the BOS.

[0197] Next, to add the entity of the sub Dir. X that has been read, theimplementation reduces a length of an area for a second entity of an SMFand adds the entity of the sub Dir. X to the resultant blank area.

[0198] Next, to reflect the change of the length of the second entity ofthe SMF, the implementation updates information of an AD-1 of an FE ofan SMF.

[0199] Next, to reflect the change of a location of the entity of thesub Dir. X, the implementation rewrites an FE of the sub Dir. X.

[0200] Next, to prohibit the defective sector from being accessed, theimplementation causes the defective sector to be excluded from the SMFthat is managed. As a result, the defective sector is not accessed.Thus, the backup can be securely performed.

[0201] Next, to reflect the change of an SMA-2 area 16, the implementrewrites the entity of the BOS.

[0202] When the entity of the BOD is referenced and the length of thesecond entity of the SMF is reduced, the defective entity of the Dir. Xcan be recovered to the management information placed in the SMA-2 area16. Thus, when the defective entity of the sub Dir. X is recovered, themanagement information is collectively placed in the SMA-2 area 16.

[0203] Since the structure of the drive apparatus according to thesecond embodiment is the same as that shown in FIG. 10, the descriptionwill be omitted.

[0204] (Third Embodiment)

[0205] According to a third embodiment, if a defect takes place ininformation that designates a record location of entity data of a file,the information can be recovered.

[0206] Since a logical format of a disc shaped record medium, a formatprocess, and a method for adding a sub Dir. or a file after a formatprocess has been performed according to the third embodiment are thesame as those according to the second embodiment, their description willbe omitted.

[0207] First of all, an operation for backing up an FE of a file in thecase that a sub Dir. or a file has been created will be described.

[0208]FIG. 16 is a schematic diagram for explaining the structures of anSMA-2 area and an SMA-3 area before a backup of a file entry of a childfile is created according to the third embodiment.

[0209]FIG. 17 is schematic diagram showing a file identifier descriptoraccording to the third embodiment.

[0210]FIG. 18 is a schematic diagram for explaining a method forcreating a backup of a file entry of a child file according to the thirdembodiment.

[0211]FIG. 19 is a schematic diagram showing a format of animplementation use according to the third embodiment.

[0212]FIG. 16 is a schematic diagram showing a linear representation ofa record area placed concentrically or spirally on a disc shaped recordmedium 10. FIG. 16A mainly shows an SMA-2 area 16. FIG. 16B mainly showsan SMA-3 area 17.

[0213] On the disc shaped record medium 10 shown in FIG. 16, by theoperations according to the first embodiment and the second embodiment,a plurality of sub Dirs. are created under a root Dir. In addition, asub Dir. and a file are created under another sub Dir. Sub Dir. X of theplurality of sub Dirs. is created under the root Dir. A child file iscreated under the sub Dir. X.

[0214] To create a sub Dir. and a file, as shown in FIG. 16A, an FE ofthe root Dir., an entity of the root Dir., an FE of a BOS, an FE of anSMF, an entity of an AD-0 of the SMF, FEs of plurality of sub Dirs.,entities of the sub Dirs, and an entity of an AD-1 of the SMF arerecorded in an SMA-2 area 16. The entity of the root Dir. is composed ofan FID of a parent Dir., an FID of the SMF, an FID of the BOS, and FIDsof sub Dirs.

[0215] As shown in FIG. 16B, an SMA-3 area 17 is composed of an entityof the BOS, an FE of a file, entity data of the file, and a blank recordarea (in which substantially meaningful information has not beenrecorded). For example, a location of an FE of a child file in the subDir. X is stored in an ICB of an FID of the child file in the entity ofthe sub Dir. X. A location of entity data of the child file is stored inthe AD-0 of the FE of the child file.

[0216] As shown in FIG. 17, in the UDF, the FID is composed ofDescriptor Tag, File Version Number, File Characteristics, Length OfFile Identifier, ICB, Length Of Implementation Use, Implementation Use,File Identifier, and Padding.

[0217] Next, the FID will be described in brief; for details, refer tothe UDF Specification. The Descriptor Tag is an identifier thatidentifies a descriptor. Tag Identifier identifies a type of adescriptor. The File Version Number represents a version number of thefile. The File Characteristics a file attribute that represents a hiddenfile, a not-hidden file, or a directory. The Length Of File Identifierrepresents the size (length) of a file ID. The ICB contains a logicaladdress and a length of an FE (as was described above). The Length OfImplementation Use represents a lengththe Implementation Use. TheImplementation Use will be described later. The File Identifier is anidentifier of the file. The Padding is placed so that the FID, which hasa variable length, becomes a multiple of four bytes.

[0218] As shown in FIG. 18, a BFE (Backed up File Entry) that is abackup of an FE of a child file is created in the SMA-3 area 17. When anFE of a regular child file is created, a spare BFE is created.

[0219] In FIG. 18, a BFE is recorded immediately after entity datadesignated thereby. Alternatively, a BFE may be recorded in any recordarea of the SMA-3 area 17.

[0220] The content of a BFE is the same as the content of an FE to bebacked up. An AD-0 of the BFE contains a logical address and a length ofentity data of a child file to be backed up.

[0221] To designate a BFE, the Implementation Use of the FID of thechild file is extended.

[0222] As shown in FIG. 19, the Implementation Use is composed of Flag,Identifier, OS Class, OS Identifier, Implementation Use Area, andLogical Block Number of Backup BFE.

[0223] The Flag, Identifier, OS Class, OS Identifier, and ImplementationUse Area comply with the standard of the UDF. The Logical Block NumberOf Backup BFE is an extended portion according to the embodiment.

[0224] Next, the Implementation Use will be described in brief; fordetails, refer to the UDF Specification. The OS Class and the OSIdentifier are cooperatively used. The OS Class and the OS Identifierrepresent an operating system (OS) on which the implementation (that isthe entire apparatus including the drive apparatus) is operating. TheImplementation Use Area is an area that the implementation can freelyuse.

[0225] The Logical Block Number of Backup BFE contains a location of aBFE that backs up a regular FE. The location of the BFE is representedby a logical block number.

[0226] The Implementation Use of the FID is also described in theImplementation Use of an FID of a child file in an entity of an BOS.

[0227] The UDF Specification is published on the home page of OSTA(Optical Storage Technology Association)(http://www.osta.org/html/ostaudf.html). Anyone can download the UDFSpecification from the home page.

[0228] Next, an operation for recovering an FE of a regular child fileplaced in an SMA-3 area 17 in the case that the FE of the child filecannot be read will be described.

[0229]FIG. 20 is a schematic diagram for explaining a process forrecovering a file entry of a child file in which a defect has takenplace.

[0230]FIG. 20 is a schematic diagram showing a linear representation ofa record area placed concentrically or spirally on a disc shaped recordmedium 10 according to the third embodiment. FIG. 20A mainly shows anSMA-2 area 16. FIG. 20B mainly shows an SMA-3 area 17.

[0231] In FIG. 20, an FID of sub Dir. X is placed in an entity of a rootDir. The FID of the sub Dir. X designates an FE of the sub Dir. X. TheFE of the sub Dir. X designates an entity of the sub Dir. X. The entityof the sub Dir. X is composed of an FID of a parent Dir., an FID of achild file, and so forth. An ICB of the FID of the child file designatesan FE of the child file.

[0232] In such a case, when the FE of the child file cannot be read dueto a defect, the Implementation references the Implementation Use of theFID of the child file.

[0233] Next, the Implementation checks the Logical Block Number ofBackup of the Implementation Use and obtains a logical block number ofthe backup BFE.

[0234] Next, the Implementation references the BFE with the logicalblock number thereof and copies the content of the BFE to a blank recordarea of the SMA-3 area 17. As a result, the Implementation recovers theFE of the regular child file.

[0235] Next, to designate the FE of the recovered child file, theImplementation rewrites the content of the ICB of the FID of the childfile in the SMA-2 area 16.

[0236] Next, to reflect the rewritten content of the ICB, theImplementation rewrites the content of the FID of the child file of theentity of the BOS of the SFA 17.

[0237] Thus, the FE of the recovered child file is newly linked. Withthe FID of the child file, the recovered FE of the child file isreferenced. As a result, entity data of the child file can be read. Evenif some defect takes place in the FID of the child file, with referenceto the FID of the child file in the entity of the BOS, the FID of thechild file is recovered. In addition, the recovered FID of the childfile designates the recovered FE of the child file.

[0238] In addition, whenever an FE of a regular child file cannot beread, with a backup BFE, the FE of the regular child file is recovered.Thus, unless both the FEs cannot be read, entity data of the file can beread.

[0239] When there are a plurality of files, there are also a pluralityof BFEs. However, these BFEs may be treated as one file. In this case,an FID of the file for the BFEs is created in the entity of the rootDir. An FE that designates these BFEs is created in the SMA-2 area 16.Since the BFEs are treated as a file, an operating system that does notsupport the BFEs cannot use a backup function for an FE of a file.However, the disc shaped record medium 10 can be treated as a recordmedium that complies with the conventional UDF. When a file attribute ofa BFE is designated, “hidden file attribute” is designated in the FID ofthe BFE. “Read only file attribute” and “system file attribute” aredesignated in the FE of the BFE.

[0240] Since the structure of the drive apparatus according to the thirdembodiment is the same as the structure of the drive apparatus shown inFIG. 10, the description will be omitted.

[0241] In the forgoing embodiments, format data for the disc shapedrecord medium 10 is created by the ENC/DEC circuit 56. However, thepresent invention is not limited to such an example. The format data canbe created by the drive controlling microcomputer 60. Alternatively, theformat data may be supplied from the digital apparatus 71.

[0242] In the forgoing embodiments, the present invention is applied todrive apparatuses such as an optical disc drive apparatus and amagneto-optical disc drive apparatus. However, the present invention isnot limited to such examples. In other words, the present invention canbe applied to a record medium drive apparatus that allows data recordedon a record medium to be managed with predetermined managementinformation, for example, a fixed drive apparatus such as a hard diskdrive apparatus.

[0243] As was described above, according to the present invention,names, addresses, lengths, and so forth of Dirs. and files managed on adisc shaped record medium are collectively recorded in a predeterminedarea (SMA-2 area) thereof. Thus, these management information can beread at high speed.

[0244] In addition, according to the present invention, sinceinformation of an initial range of an area (a second entity of an SMF)that stores information with respect to a sub Dir. and a file under aroot Dir. that are added after a format process is performed has beenrecorded on a disc shaped record medium, regardless of locations of anFE of the root Dir. and an FE of the SMF, the SMA-2 area can bedesignated.

[0245] In addition, according to the present invention, a blank area ofan SMA-2 area is managed as a file. In addition, after a format processhas been performed, when a sub Dir. and a file are added and then theyare deleted, although a blank area takes place, it is managed as a partof a file. Thus, the another OS is prevented from writing the SMA-2area.

[0246] In addition, according to the present invention, since a specialattribute is designated to a file managed as a blank area of the SMA-2area, another OS is prevented from deleting the file managed as theblank area.

[0247] Alternatively, according to the present invention, managementinformation for managing the hierarchical structure of the file systemis collectively recorded in a predetermined area as a particular file.In addition, since the management information is copied as a backupfile, even if a defect takes place in a part of the original managementinformation, the backup file can be recovered to a predetermined area ofwhich a particular file is deleted. Thus, after a recovery from adefect, by reading the original management information rather than abackup file, the drive apparatus can recognize the hierarchicalstructure of the file system. In addition, when the drive apparatus isrecovered from a defect, since the management information iscollectively recorded in a predetermined area, the drive apparatus canread the management information at high speed.

[0248] In addition, according to the present invention, sinceinformation with respect to an initial location and an initial length ofa particular file and information with respect to a current location anda current length of the particular file are recorded in a particulararea, the drive apparatus can securely recognize a location and a lengthof the particular area.

[0249] In addition, according to the present invention, since adefective sector in which a defect has taken place is not excluded froma particular file that is managed, the defective sector can beprohibited from being accessed. Thus, a backup file can be securelycreated.

[0250] In addition, according to the present invention, when an SMA-2area that has been allocated in a format process becomes full, byrewriting only information of a file managed as a blank area of theSMA-2 area, it can be extended.

[0251] Alternatively, according to the present invention, sinceinformation that designates a location of entity data of a file isdually recorded, the security of the information can be improved.

[0252] In addition, according to the present invention, when regularinformation cannot be read due to an occurrence of a defect, usingbackup information, the regular information can be newly recovered tothe record medium. Thus, even if the regular information cannot be read,entity data of a file can be read.

[0253] In addition, according to the present invention, whenever regularinformation cannot be read, it is recovered with backup information.Thus, unless both the regular information and the backup informationcannot be read, entity data of a file can be read.

1. A recording method for recording data to a disc shaped record mediumcorresponding to a hierarchical file system, the method comprising thesteps of: recording management information for managing a hierarchicalstructure of the file system to a particular area of the disc shapedrecord medium; treating an unused area of the particular area as aparticular file; and recording information with respect to an initiallocation and an initial length of the particular file and informationwith respect to a current location and a current length of theparticular file to the particular area.
 2. A recording method forrecording data to a record medium corresponding to a hierarchical filesystem, the method comprising the steps of: recording managementinformation for managing a hierarchical structure of the file system toa particular area of the record medium; treating an unused area of theparticular area as a particular file; copying all the particular area toanother area as it is and treating all the copied particular area as onebackup file; and if a part of the management information cannot be read,reducing a length of the particular file, creating a blank portion ofthe particular area, and recovering the part of the managementinformation that cannot be read with data corresponding to the part ofthe backup file in the blank portion of the particular area.
 3. Arecording method for recording data to a record medium corresponding toa hierarchical file system, the method comprising the steps of:recording management information for managing a hierarchical structureof the file system to a particular area of the record medium; treatingan unused area of the particular area as a particular file; duallyrecording information that designates a record location of entity dataof a file as regular information and backup information to the recordmedium; and reducing a length of the particular file, creating a blankarea of the particular area, and recording designation information thatdesignates record locations of the regular information and the backupinformation to the blank area of the particular area.
 4. The recordingmethod as set forth in claim 1, further comprising the steps of: whenthe management information is added to the particular area, reducing alength of the particular file corresponding to the managementinformation that is added and creating a blank portion of the particulararea; and recording the management information that is added in theblank portion of the particular area.
 5. The recording method as setforth in claim 1, further comprising the step of: when the managementinformation that has been added is deleted, if the managementinformation that is deleted is in an initial area of the particularfile, recording information with respect to a location and a length of ablank portion of which the management information has been deleted inthe particular area.
 6. The recording method as set forth in claim 1,further comprising the step of: designating a hidden file attribute, asystem file attribute, and a read only file attribute to the particularfile.
 7. The recording method as set forth in claim 2 or 3, furthercomprising the step of: recording information with respect to an initiallocation and an initial length of the particular file and informationwith respect to a current location and a current length of theparticular file to the particular area.
 8. The recording method as setforth in claim 1 or 7, further comprising the step of: when theparticular area runs out of an area to which the management informationis newly added, designating a new particular file to an unused area ofthe disc shaped record medium, recording information with respect to aninitial location and an initial length of the new particular file andinformation with respect to a current location and a current length ofthe new particular file to the particular area so as to extend an areaof the particular file.
 9. The recording method as set forth in claim 2,further comprising the steps of: when the management information isadded to the particular area, reducing a length of the particular filecorresponding to the management information that is added and creating ablank portion of the particular area; recording the managementinformation that is added in the blank portion of the particular area;and updating the backup file corresponding to the management informationthat is added.
 10. The recording method as set forth in claim 3, furthercomprising the step of: when the regular information cannot be read,recovering the regular information with the backup information to therecord medium.
 11. The recording method as set forth in claim 3, furthercomprising the steps of: copying all the particular area to another areaas it is and treating all the copied particular area as one backup file;and if a part of the management information cannot be read, reducing alength of the particular file, creating a blank portion of theparticular area and recovering the part of the management informationthat cannot be read with data corresponding to the part of the backupfile in the blank portion of the particular area.
 12. A recordingapparatus that records data to a disc shaped record medium correspondingto a hierarchical file system, the apparatus comprising: means forrecording management information for managing a hierarchical structureof the file system to a particular area of the disc shaped recordmedium; means for treating an unused area of the particular area as aparticular file; and means for recording information with respect to aninitial location and an initial length of the particular file andinformation with respect to a current location and a current length ofthe particular file to the particular area.
 13. A recording apparatusthat records data to a record medium corresponding to a hierarchicalfile system, the apparatus comprising: means for recording managementinformation for managing a hierarchical structure of the file system toa particular area of the record medium; means for treating an unusedarea of the particular area as a particular file; means for copying allthe particular area to another area as it is and treating all the copiedparticular area as one backup file; and means for reducing a length ofthe particular file, creating a blank portion of the particular area,and recovering a part of the management information that cannot be readwith data corresponding to the part of the backup file in the blankportion of the particular area, if the part of the managementinformation cannot be read.
 14. A recording apparatus that records datato a record medium corresponding to a hierarchical file system, theapparatus comprising: means for recording management information formanaging a hierarchical structure of the file system to a particulararea of the record medium; means for treating an unused area of theparticular area as a particular file; means for dually recordinginformation that designates a record location of entity data of a fileas regular information and backup information to the record medium; andmeans for reducing a length of the particular file, creating a blankarea of the particular area, and recording designation information thatdesignates record locations of the regular information and the backupinformation to the blank area of the particular area.
 15. A disc shapedrecord medium on which data is recorded corresponding to a hierarchicalfile system, management information for managing a hierarchicalstructure of the file system being recorded to a particular area of thedisc shaped record medium, an unused area of the particular area beingtreated as a particular file, information with respect to an initiallocation and an initial length of the particular file and informationwith respect to a current location and a current length of theparticular file being recorded to the particular area.